Multiplex photocopier system with portable scanner

ABSTRACT

A multiplexing electrostatic copier system employing one or more detachable portable optical reader units, each including a &#34;memory&#34; or recorder, that may be readily carried about by a user for temporarily recording a &#34;video&#34; image of a printed document or other object to be copied or reproduced. For reproducing the recorded video image, the portable units are selectively connectable to an electrostatic copy making machine at the convenience of the users to transfer the remembered or recorded &#34;video&#34; images to the copy machine for reproducing the stored images and preparing a hard copy of the original document, e.g. a printed copy document on paper. The copier machine may also provide an advanced visual display of each of the transferred &#34;video&#34; images, enabling the users to initially observe the images before the hard copies are made.

COPENDING APPLICATIONS

This application is a division of Ser. No. 084,851 of Dec. 4, 1979 andSer. No. 925,290 filed July 17, 1978 now U.S. Pat. No. 4,251,153 whichis a continuation-in-part of earlier application Ser. No. 718,260, filedAug. 27, 1976, now U.S. Pat. No. 4,182,569 and also of earlierapplication Ser. No. 775,480, filed Mar. 8, 1977 now abandoned.

BACKGROUND OF THE INVENTION

This invention generally relates to improvements in multiplexedphotocopier systems, to provide greater capability and greaterflexibility than those presently available.

In earlier application Ser. No. 718,260 referred to above, there isdisclosed a multiplexed photocopier system having a number ofindependently usable optical reader stations that are multiplexed with alesser number of developing and paper feeding mechanisms, enabling anumber of users to concurrently use the different scanner stations formaking copies. The developing system operates in either a simultaneousmode or in an overlapping time sequence mode, automatically deliveringthe copies back to the originating station.

In earlier application Ser. No. 775,480, an "adjustable capacity"multiplexed photocopier system of this same kind is provided in whichthe various functional units of the machine are supplied in the form ofseperately housed modules that can be readily interconnected andinterfaced with one another in different arrangemen to "tailor make" thecopier capacity needs of a particular customer. Thus, for example, aseries of separately housed optical reader modules can be coupled to anappropriate lesser number of separate developer modules to supply adesired capacity; and additionally, further optical modules or developermodules may be later added, or some removed, to adjustably change the"capacity" of the system should the needs of that customer increase ordecrease at a later time; or to replace any of the modules should theybecome inoperable or require repair.

SUMMARY OF THE INVENTION

According to the present invention, there is disclosed a similarmultiplexed system, but having at least one or more of the opticalreaders in the form of portable self-contained units, like "cameras",that may be carried about by the users free of connection with theseperate "developer" modules and that may operate in an "off-line"manner to store and record the "video images" observed by the portableunits, for later development by a developing machine. In operation, theusers employ the portable units, like cameras, to observe and recorddocuments to be copied, at times and locations where a conventional copymachine is not available or not convenient. At such later time and placewhere a developing machine is available, the recording is "played-back"to the machine, visually observed on a display panel and reproduced inthe form of a hard copy.

In one preferred embodiment, the portable optical reader may comprise ahand held optical scanner stylus and a portable magnetic recorder forincrementally recording the "video" signal as the stylus manually scansthe page of printing or graphics. Alternatively, a solid-state cameramay be employed to observe the entire page and its contents be read-outto an electronic memory or magnetic recorder. The developer module isprovided with a sufficient capacity to receive and service a number ofsuch portable hand scanner units, or casettes in the multiplexed fashionpreviously described in the earlier applications, or may be constructedto provide multiplexed service for a combination of both fixed opticreader stations and such portable units, as might be desired.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a system according to the invention,showing a stationary developer module and a portable optical reader unitthat is detachably connectable to the developer module,

FIG. 2 is a electrical schematic illustration of the portable electricalreader unit and a magnetic cassette recorder unit,

FIG. 3 is an electrical block diagram of the circuitry in the stationarydeveloper module,

FIG. 4 is a perspective view of the housing of a multiplexed developermodule having plural stationary reader stations,

FIG. 5 is a electrical block diagram illustrating the multiplexedelectrostatic copy developer system, functioning in a on-line andoff-line mode of operation,

FIG. 6 is an electrical block diagram of a multiplexed electrostaticdeveloper system functioning in a simultaneous mode,

FIG. 7 is a plan view of a templet for guiding a self-scanning portableoptical transducer.

FIG. 8 is a sectional view illustrating the use of the self-scanningportable transducer and templet of FIG. 7 on a document to be copied,

FIG. 9 is a schematic illustration of a paper feed and handling systemfor automatically separating and delivering copies originating fromdifferent users to different copy outlets;

FIG. 10 is a schematic illustration of a different kind of portableoptical "camera" for reading and temporarily storing the "video images"from printed documents to be copied,

FIG. 11 is an electrical block diagram illustrating the automaticshut-off and display system in the event of malfunction, and

FIG. 12 is an electrical block diagram, illustrating the circuitry ofFIG. 5.

FIG. 13 is a perspective view schematically illustrating a modularmultiplexing system according to the invention,

FIGS. 14 and 15 are perspective views, similar to FIG. 13, showing otherconfigurations,

FIGS. 16 and 17 are plan views that schematically illustrate still othermodular system configurations, and

FIG. 18 is a plan view of a room illustrating the arrangement of anumber of different modular system configurations inside the room.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, there is schematically shown in FIG. 1 aportable optical hand scanner unit 100 or "camera" disposed over thepages of a document to be copied, such as the open leave of a book 101.The hand scanner 100 is coupled by a flexible electrical cable 102 to aportable, battery operated magnetic cassette recorder unit 103 where amagnetic recording of the "video" data scanned by the optical reader isincrementally recorded as the scanner reads the document, together witha control signal having a changing value related to the rate of movementof the hand operated scanner 100, as will be discussed in greater detailbelow. The magnetic cassette recorder unit 103 may itself be aconventional type of small, portable, constant speed, battery operatedunit, as is presently available on the open market, modified to theextent of providing an additional recording track 12 and recording headfor recording a "speed" control signal in a seperate magnetic track 124alongside the track 122 having the "video" data signal. The cassetterecorder unit 103 is provided with a readout cable 104 and detachableplug connector 105, as shown, for detachable interconnection with amating plug receptacle 106 disposed on a stationary electrostaticdeveloper module 107.

As will be described in greater detail below, the developer module 107is preferably a self-contained, multiplexed, electrostatic copier unithaving, in addition, one or more attached, stationary optical readingstations 108, and including in its interior an electrostatic developingmechanism and paper feed mechanism for providing hard copy reproductionsof the documents to be copied.

The stationary developer module unit 107 includes one or morereceptacles 106 for detachably receiving the play-back plugs 105 fromthe outlet cables 104 of the portable magnetic cassette recorders 103,or a slot [not shown] for receiving the magnetic cassette, and alsoincludes various internal interfaces and internal controls, to bedescribed, for receiving and multiplexing the recorded "video" signalfrom the portable magnetic cassette unit 103, to provide hard copyreproductions of the documents 101 scanned by any one of the portablehand readers 100.

In a preferred embodiment, the electrostatic developer unit 107 stillfurther includes one or more video display screens 109 for visuallydisplaying the "video" image played back from the magnetic cassetterecorders 103, and may also include coin operated switch controls 110together with various "on-off", "light-dark" and other copy mailingcontrols 111, as are customarily supplied on conventional copy machines.

For copying documents, the user manually sweeps his portable opticalhand reader unit 100 across the page of the document 101 to be copied,traversing entire page in a number of vertically displaced horizontalsweeps to cover the printed image to be copied. An internally locatedoptical sensor within the hand scanner 100 incrementally observes theimage, and provides an incrementally changing analog electrical datasignal that varies in intensity with the light-dark areas of the printedimage as it is scanned. This analog signal is magnetically recorded bythe magnetic cassette recorder 103 in a conventional fashion to providea magnetically "stored," video image of the printed document to becopied. This "stored" image of the page or pages is retained in theportable magnetic cassette 103 until such time as a copy machine isconventionally available or when the user desires to make a hard copyreproduction. At that time the user plugs the portable recorder 103, byoutlet plug 105, into an available stationary copy making machine 107,turns on the machine, and the machine 107 receives the recorded videoimage by play-back from the cassette 103 and prepares and delivers ahard copy reproduction thereof. Alternatively, the machine 107 may beprovided with a cassette receptacle [not shown] to receive the recordedcassette from record 103 and play-back and reproduce its contents.

As shown in FIG. 2 the portable hand scanner unit 100 includes a batterypowered light 115 for illuminating the printed or graphic data on thepage 101 and a photosensor 116, including a bank of photocells or anintegrated charge coupled device. The sensor 116 receives the reflectedlight that incrementally changes in intensity corresponding to changesin the black-white image as the scanner traverses the page. This analogdata signal from photosensor 110 is suitably amplified at 120 andapplied to a first recording head 121 in the cassette recorder 103 torecord the "video" data signal on a first track 122 of the magnetictape.

A miniature tachometer 117 is also provided inside the hand scanner unit100 and driven by a friction wheel 118 that engages the surface ofdocument 101 as the hand scanner 100 is manually swept across the sheet101 during each horizontal scan. This tachometer 117 produces a variablefrequency "control" signal proportional to the changing speed ofmovement of the hand scanner 100, and this "control" signal is amplifiedat 123 and applied to a second record head 125 for recording a variablefrequency analog "control" signal on the second track 124 disposedalongside the "video" data track 122. Since the magnetic cassette tapeis driven during recording at a substantially constant speed by abattery 127 powering its motor drive 126, it will be noted that thevideo signal being recorded on track 122 will be entered on the tape ata variable rate, that varies with the speed of manual movement of thehand scanner 100 over the page. The frequency of the "control" signalbeing recorded on the second track 125 from the tachometer 117 alsocorrespondingly varies according to the speed of movement of the handscanner 100 across the page 101. Accordingly, to obtain a uniform orconstant read-out of the recorded video "data" signal regardless ofvariations in the speed of hand scanning the document 101, the speed ofthe cassette drive during playback is automatically driven at a variablespeed in opposite proportion to the variations in the frequency of therecorded "control" signal. Thus where the recorded TACH signal frequencyincreases, the playback drive is correspondingly slowed down, and whenit decreases, the speed is correspondingly increased.

Returning to FIG. 2., to obtain a constant rate play-back of the"stored" "video" signal from the magnetic cassette tape to thestationary developer module 107, a desired constant reference ac signalis produced by the developer module unit 107 and applied over line 121.This desired constant rate signal is compared in a comparator 129 withthe variable frequency ac "control" obtained during playback from thesecond track 122 of the tape [TACH signal], and the "error" signal ordifference between these two signals obtained at 129 is amplified at 131to adjustably control the speed of play-back drive motor 126, to reduceor minimize this error. In this manner, by varying the drive speed ofthe magnetic tape during playback, the recorded "video" track 122 isplayed back at a variable speed in opposition to the variations in thespeed of scanning of the hand scanner 100 during the initial scanning ofthe page, thereby to provide an effectively constant scanning of thedocument 101 despite variations in the manual speed of the hand scanner100. Thus during hand scanning of the document 101, the video signalfrom the manual scanner 100 erroneously records the "video" at a rateproportional to any variations or changes in the rate of manual movementof the stylus. However, during playback, these manual errors arecorrected by playing-back the magnetic record at changing speeds inopposition to the recording speed errors.

For energizing the motor 126 of the magnetic cassette during playback, adc power signal is produced in the developer module unit 107 and isapplied over line 128 to the portable cassette unit 103. This powersignal is applied to a logic circuit 130 an thense to a battery-relaycircuit 127 to disconnect the internal battery (not shown) within thecassette recorder unit 103 and to substitute dc power signal 128 fromthe developer module 107 to drive the cassette motor 126. As discussedabove, the play-back motor control circuitry varies the speed of motor126 during play-back according to the speed "error" derived from therecorded "control" signal to provide a constant "video" playback of therecorded information.

FIG. 3 illustrates in electrical block diagram form, details of thecircuitry of the multiplexed developer module 107, for receiving therecorded video "data" signal from the portable scanner unit 100 andmagnetic cassette unit 103 and for producing a visual display of therecorded video "data", as well as a hard copy reproduction thereof.

As shown, when the user of a portable scanner unit desires to reproducea magnetically "stored" video image, or images that have been previouslyrecorded, the detachable plug 105 from the portable recording unit isinserted into any available receptacle 106 of a stationary developermodule 107. This interconnects the play-back video "data" lines 141, 142from the magnetic cassette play-back heads to the developer module 107as well as connecting the dc power source 154 of the module over line153 to the line 128 of the cassette recorder 103. This plug alsoconnects the ac "reference speed" line from source 156 in the module 107over line 155 to input line 132 of the cassette recorder 103. Within thestationary developer module 107 all of these lines also pass through thevisual display control switch panel 150 and coin operated switches 170;and upon the user actuating the switches 150 and 170, the system isplaced into operation to provide a visual display on unit 160 of therecorded video "data" from the portable cassette recording 103 unit.

Referring to FIG. 3, the data lines 141, 142 from the play-back heads ofthe magnetic cassette are initially connected through the visual displayswitching panel 150 to a display control circuit 157, that permits theadjustment of light intensity of the display and provides otherconventional controls and adjustments governing the visual display at160. Thereafter these "video" "data" signals are directed to an analogbuffer storage unit 159 where the video "data" signals are againtemporarily recorded for syncronization with a TV visual display 160. Aswill be appreciated, the buffer storage unit 159 preferably operates asa continuous recording and playback device that is speed controlled bythe same reference clock 158 that controls the scanning of the TV typevisual display 160. The video "data" signals from the portable recordingcassette 103 are therefore played back from buffer storage 159 andapplied to the display 160 in a synchronized manner to yield a visualdisplay of the previously recorded image of the document. The videodisplay switch panel 150 also applies the dc drive power signal from 154to line 128 of the recorder 103 for driving the portable magneticcassette unit 103 during playback, and applies the ac speed referencesignal from 156 through the switch panel 150 to line 132 of the cassetterecorder 103 to provide the playback speed reference signal forcontrolling the speed of playback of the magnetic cassette tape.Therefore, upon the user plugging in his portable video recording unit103 to the stationary developer module 107, and upon actuating thevisual display panel switch 150 (operated by panel knob 111 in FIG. 1),the recorded "video" image from the portable magnetic cassette 103 isplayed back and entered into the buffer storage unit 159, and from thereis applied in synchronism to the TV display 160 for displaying a visualimage of the previously recorded page.

It will be apparent that the purpose of providing an initial visualdisplay of the recorded image prior to making a hard copy reproductionthereof is to insure that a satisfactory recording of the desireddocument has been initially recorded by the portable stylus unit 100. Iffor some reason, the desired image from page 101 has not beensatisfactorily recorded, the user is then free to erase the improper orincomplete magnetic recording from his cassette recorder 103 and toreturn the portable scanner 100 and rescan the text 101 (FIG. 1) andthereby provide a complete or accurate recorded image thereof.

After being satisfied by the visual display 160 that a correct image ofthe document desired has been "stored" on the magnetic cassette tape,the user then inserts the required payment to operate the coincontrolled switch panel 170. Operation of this switch panel 170 appliesthe cassette playback drive power from 154 to the cassette playbackmotor as well as applying the speed reference ac signal to control thevariable playback speed of the magnetic cassette 103. Playback of themagnetic cassette 103 in this case transfers the recorded video "data"signals over lines 172 and 173 to the video image storage buffer 171,where the data signal is temporarily stored in readiness for applicationto the photoconductor 175 in the copy making or reproduction portion ofthe developer module 107.

As previously described in Applicant's earlier patent applicationsdiscussed above, and as is shown in FIGS. 3, 4, 5, and 6 in themultiplexed developer module such as in unit 107 (in FIG. there isincluded a plurality of independently usable optical reader or scanstations that are multiplexed to a lesser number of development units sothat a number of different users can independently make use of the samemachine by "time-sharing" the same developing apparatus. Thus as isshown in FIG. 4, at least three optical scanner stations 11, 12, and 13are provided as an integral part of the same common module 10, and aremultiplexed a common development and paper feed mechanism in a manner asshown in FIGS. 5 and 6.

As described in greater detail in the earlier applications discussedabove, FIG. 5 shows a multiplexing system having two such scan stations30 and 31 selectively feeding video images to a common electrostaticcopy developing mechanism, including a single common photoconductor 41.In this mode, when one of the optical reader stations 30 or 31 is placedin operation, with the other being idle, the machine functions in adirect customary manner by applying the scanned optical image directlyto the photoconductor 41 after it has been previously charged by chargeunit 43. This charged optical image is then developed by applying tonerliquid or particles from 44, and the developed image is transferred tocopy paper, supplied from a feed 42, and finally the copy is deliveredto the proper one of copy outlets 45 or 46 corresponding to that one ofthe scan stations 30 or 31 where the image originates. In the event thatthe other one of the scan stations 31 or 30 is placed in operation whilethe first station is cycling, the scan image from the other readystation is recorded in an available image storage unit 32 or 33, for"off-line" operation, awaiting availability of the common developermechanism. When the common developer mechanism has completed itsresponse to the first operated optical station, it then automaticallyresponds to any "stored" images, to again cycle and develop any "stored"images as may exist in storage units 32 or 33.

Each of these different optical reader stations is provided with its ownassociated copy receiving outlet, shown in FIG. 4, at 15, 17, and 19, orin FIG. 5 as 45 and 46, and each hard copy being made is automaticallydirected to the correct one of these outlet where that image originated.As previously described, this is performed by having each optical readerstation 30 and 31 produce its own distinctive digital code or markingsignal along with transmitting the image or signals from the image to becopied. This code or mark is stored and/or developed and is reproducedon the copy sheet in the same manner as is the copied image. Afterdevelopment the digital code on the copy sheet is suitably detectedinside the module, as will be described, to recognize the originatingreading station and to divert that copy document to its proper outlet.

As previously described, it is preferred to employ a microprocessor andrelated controls 40 to perform these off-line and on-line multiplexingfunctions as described, since such devices are now standard, on theshelf, integrated chips that have both adequate read-only memory "ROM"capacity, to store an adequate program of instructions, as well asrandom access memory, "RAM" capacity, to store various controlconditions. Furthermore, such chips can all be employed with readilyavailable sensors to monitor the different functions of the machine andto shut off or disable the machine, different components thereof, whenthe machine or its parts is not functioning in a proper manner. Ifdesired, each optical reader station may also be provided with anindicator panel, to be described, that provides desired signals ormessages, in visual and or audible form, informing the user of somemalfunction, or instructing about the need for adding toner, paper, orthe like. These indicator functions and instruction functions may alsobe performed under control of the same, or additional microprocessors,or by the use of descrete tailored microelectronic components, as willbe described.

FIG. 6, shows the operation of the same or a different machine that ismultiplexed to provide simultaneous development of image from pluraloptical reader stations 56 and 57. Here the plural images are appliedsimultaneously, or when received, to different areas or regions of anelongated photoconductor 51 in the form of an elongated belt 51 or drum.All of the images are developed during a single cycling of the developermechanism, by using a common charger 55, common toner 58, common paperfeed 59 and the like. A microprocessor 63, or equivalent in discretecircuitry, responds to suitable sensors detecting the operation of eachoptical scan station to properly control the charger 55, toner mechanism58 a other mechanisms, to develop all images during each cycle, and todivert the copies to the proper outlets associated with the differentoptical reader stations.

Where it is desired that the machine always operate in a substantiallysimultaneous development mode (without storage), regardless of whetherthe optical reader stations are operated simultaneously, or in differenttime sequence, each optical station 56 and 57 is monitored, as well asmonitoring the position or locations of latent images on thephotoconductor 51. By continually monitoring all of these conditions itis known whether a position of the charged photoconductor immediatelybeneath a given optical readed station is available to receive a latentoptical image from that station, or whether that optical reader shouldbe momentarily delayed in scanning awaiting the availability of anunexposed port of the photoconductor 51 (to prevent overlapping of twoimages). Where overlapping might occur, that optical reader station isbriefly time delayed, in its scanning of the document, and then secondslater, it is activated to apply its image to a "clean" portion of thephotoconductor drum or belt 51. A microprocessor 63 is preferablyemployed to control the simultaneous mode of operation of FIG. 6, aswell as in the "off-line" mode of FIG. 5. However, it will beappreciated that discrete electronic circuit may be employed for thesefunctions, as will be described.

Returning to FIG. 3, the developer module 107 as employed with portablescanner 100, preferably includes a multiplexing system of the same kindshown in FIGS. 5 or 6, employing a common photoconductor 175 (FIG. 3)and associated components controlled by a microprocessor 177, to developimages received from both one or more stationary optical reader stationsattached to the machine, as well as from one or more portable opticalscanner units 100 and associated magnetic cassette recorders 103. In asimilar manner as previously described, the operation one of thestationary optical reader stations 108 directly applied its opticalimage to the photoconductor 175 in a "on-line" manner to initiate adevelopment cycle. Alternatively, if the developed mechanism is alreadycycling at the time such stationary reader station 108 is activated, itsimage may be temporarily stored in an "off-line" manner by a buffer orimage memory 176, and the stored image later applied to thephotoconductor 177 for development. However, with respect to the use ofportable reader units 100, on the other hand, the generated opticalimages produced by the portable units are always stored (off-line) in aportable magnetic cassette recorder 103. Therefore upon activation ofthe developer mechanism 107 by operation of the coin operated switch170, the portable cassette recorder 103 is played back over data lines141 and 142 and then over lines 172 and 173 to image storage buffer 171,and thence to the photoconductor 175 for ultimate development of a hardcopy reproduction.

As an alternative to manually applied scanning of the transducer 100 asdescribed in FIG. 2 and FIG. 3, a constant speed, motor driven portablescanner 180 may be employed as is illustrated in FIGS. 7 and 8. In thismodification, the portable transducer 180 includes a battery poweredconstant speed motor 182 and friction drive wheel 183, for engaging thesurface of a mask or templet overlay 181 that is disposed directly ontop of the document 101 to be copied. The templet 181 is in the form ofa flat, transparent panel having a continuous guiding groove 184 forguiding the reader 180, provided in the form of a connected series ofvertically separated horizontal lines 184 extending to encompasssubstantially the entire surface area of the templet 181 thereby toguide the motor driven transducer 180 in a series of horizontal sweepsto scan the entire page of the document. As best shown in FIG. 8, theoptical reader or transducer 180 includes a light source 186, focusinglenses 187, and a photocell bank 188 for reading the printed lines orgraphic data on document 101 as the reader 107 travels at constant speedacross the templet 181 to read the lines of the print or other image.The scanner 180 includes a downwardly extending guide arm 189 projectinginto the continuous guide groove 184 of the templet 181, thereby toguide the reader 180 along its continuously guided scanning path 184(FIG. 7). Since the spacing and size of the printed lines or graphicdata of the text to be copied varies for different texts and documentsto be copied, the vertical spacing apart of the guide groove 184 linesdoes not attempt to conform with the spacing between printed lines onany particular document, but merely insures that the entire page 101 ofdata is "read" or scanned by the traveling transducer 180. The size ofthe optical beam of light 186, the design of the focusing lenses 187,and the banks of photocells 188 are all so designed as to read ahorizontal band or area for each sweep that may encompass one or morelines or sections of a graphic area. As noted above, the templet 181 ispreferably made of transparent plastic material or the like, forenabling the scanning light beam 186 and reflected rays to pass throughthe transparent templet 181 for reading the contents of the text or dataas it travels across the page of the text 101.

It will be appreciated that with a constant speed motor driven opticalreader of FIG. 7, the data being read from the page is entered into themagnetic cassette 103 (FIG. 1) at a uniform rate. Accordingly, it is notnecessary to record a separate additional variable frequency "control"signal on a second magnetic track 124 as described above (and shown inFIG. 2), nor is it necessary to reproduce or playback the magneticallyrecorded cassette tape at a variable speed as previously described.Instead, the data from document 101 to be copied may be both recordedand reproduced at a constant speed cassette drive.

To copy a document 101 in this case, the user merely energizes theconstant speed drive motor 182 in the portable reader unit 180, andreleases the reader 180 in position at the upper left hand corner of thetemplet 181 with its guide arm 189 being engaged in the guide groove 184of the templet 181. The transducer or optical reader 180 is thereafterself-driven by its motor 182 at constant speed to entirely scan the page101, following the continuous guide groove 184 in the templet at aconstant speed of travel. The magnetically recorded data in the cassette103 reproduced in the stationary developer module 107 (FIG. 1) for aninitial visual display of the document 101 on the video display panel109, as well as being entered into the video image storage buffer 171(FIG. 3) in readiness for producing a hard copy printed reproduction.Where the recorded "data" in the magnetic cassette 103 is reproduced ata constant speed, the cassette playback drive power signal from 154 andspeed reference signal from 165 (FIG. 3) may be dispensed with ordisconnected.

It will be appreciated that the developer module 107 of FIG. 1 may beprovided with a number of stationary optical scanner stations, such as108, as well as with a number of cassette playback receptacles 106, andassociat equipments, for use by portable optical readers and recorders,such as units 101 and 103 of FIG. 1. On the other hand, if desired,multiplexed developer modules 107 may be provided without stationaryoptical scan stations 108 for use only with portable readers. Aspreviously described, the optical readers, whether stationary orportable, are adapted to be multiplexed with a common developerapparatus, as is described above in FIGS. 5 and 6. Additionally, in theevent that the developer module 107 is equipped to service a number ofportable optical scanners 101, it is preferably provided with a similarnumber of video display panels 109, and associated equipments, forimmediate visual display from any plugged-in portable optical reader 100and/or magnetic cassette 103 reproducer. Alternatively, a lesser numberof such video display panels 109 may be used than the number of portablereader receptacles 106, and the portable optical readers 101 may bemultiplexed to await their term and "time share" the lesser number ofvideo display panels.

In the embodiments described above, the printed or graphic data to becopied is optically read from the document 101 and magnetically storedin the form of analog signals in a portable magnetic cassette recorder103. Available magnetic recorders for audio signals, as well as videosignals, are capable of recording up to one hour or more in time, thatis more than sufficient for recording a number of printed or graphicallyrecorded documents. The user is therefore not required to reproduce ortranscribe each document after it is optically scanned and magneticallyrecorded but instead may retain his magnetic record for a period of timeand use it to record and store a number of different documents. Aftereach document is magnetically recorded, the cassette 103 may internallyincorporate a tagging generator (not shown) that is actuated by the userto record a detectable "end-of-document" signal or a code on themagnetic tape, as well as operating an odometer or a counter tocontinuously indicate the number of documents that have been previouslyrecorded. This control information may be used for manual control or forautomatic retrieval, to select and visually display any one of thepreviously magnetically recorded documents on the display panel 109 ofthe developer module 107, or may be used to selectively reproduce andproduce hard copies of any one or more of the magnetically storeddocuments. Thus, for example, the user may desire to visually display insequence all of the documents previously read and magnetically recorded,to insure that his records are complete and accurate, but he may wish tomake hard printed copies of only selected ones of the magneticallyrecorded documents. This is readily accomplished in a manual fashion, byhaving the developer module 107 respond to the receipt of each"end-of-document" recorded code to generate a signal back to 'stop" theplayback of the magnetic cassette 103. Thus enables the user toselectively and controllably advance his magnetic tape to the nextdesired recorded document he wishes to copy, skipping the others, andusing the record odometer or counter to inform him when the correctportion of the tape is reached. It will be evident that these samefunctions may also be readily performed in an automatic manner, ifdesired, by known automatic document retrieval methods using the"end-of-document" codes on the tape.

Although "analog" recording of the document data is presently consideredto be more desirable due to the advantages of having available equipmentat reasonable cost, that enables the long time (many documents)recording, it is also well known to provide digital recording andmagnetic storage. For example, the U.S. Phillips company employs one ormore "RAMS" (Random Access Memory or uses shift registers, for storageof video signals as disclosed in its U.S. Pat. No. 3,993,865. Similarlythe Japanese company, Ricoh LTD of Tokyo, Japan, digitizes video signalsusing a threshold circuit and sampler, and stores the digitized videopulses alternately in a pair of buffer shift registers, as disclosed inU.S. Pat. No. 3,800,000.

A still further advantage, at present, of using analog magneticrecording employing a magnetic cassette recorder, is that additionalcassettes can be readily inserted as each becomes filled with recordeddata from documents. On the shelf "storage time" for magnetic records isquite long, and therefore "hard" paper copies need not be made from themagnetic recording until needed, or at the convenience of the user, orupon the availability of a developer module 107. The magnetic tapes mayalso be repetitively replayed without erasure over and over again tomake multiple hard copies, at different times, if needed; or the tapesmay be erased and rerecorded over and over again when the previouslyrecorded documents are no longer needed. Equivalent recording mechanismsmay also be provided for making multiple copies where digital componentsare used for storage, although the digital components are not yet asconvenient, or inexpensive, according to the present state of the art.

In the embodient of FIG. 7, the templet 181 is employed with a motordriven optical reader 180, wherein the reader 180 automatically "runs"over the page 101, following the path of the continuous templet guidegrooves 184 to control its direction of movement. For the manuallypositionable optical scanner 100 of FIG. 1, a similar templet 181 havinga guide groove 184, may also be used to guide the portable reader 100,and to insure that the page 101 is completely scanned in a series ofproperly displaced parallel lines. In either the motor driven ormanually driven optical reader, the templet may be otherwise configuredto guide the reader to follow other scan patterns, such as a spiral scanpattern (not shown), or other.

FIG. 13 shows a modular multiplexed system according to the inventionfor the purpose of enabling different users to be individually providedwith different copier cababilities to conform with their individualneeds. In the above mentioned earliest application, such a modularsystem is briefly described as having a central or master modular unit,that may include a common development apparatus, and one or moresatellite units having optical scanners that are detachably connectableto the master unit, to enable expansion or reduction of the copy makingcapacity by providing a greater or lesser number of optical scanstations.

In the embodiment of FIG. 13, there is shown a separate master module370, a separate satellite module 371, and a separate common developmentand paper feed and supply module 372; all three modules beinginterconnectable to one another by electrical cabling 373, 374 that ispart of a universal bus system that interfaces the modules. In thisembodiment, the master module 370 has four optical scan stations 375,376, 377 and 378 provided in an arcuately shaped cabinet, and thesatellite module 371 has an additional four scanners 379 to 382,inclusive, totaling eight optical input scan stations in all. The commoncontrol and supply module 372 contains a common development mechanism,or plural development mechanisms, a paper supply and feed mechanism, ormechanisms, and at least some of the control mechanisms, that mayinclude descre circuitry and a digital data processor or microprocessor.A total of eight outlet chutes 375a to 382a are provided to eachcorrespond with each different one of the optical scan stations in boththe master module 370 and satellite module 371. It will be appreciatedthat in this construction, each of the eight optical scanners 375 to 382converts its scanned optical image to an electrical video signal that istransmitted over the universal bus system 373, 374 to the developermodule 372 where the video signal is developed "on-line" or stored"off-line" and later developed, depending upon whether the sequentialmultiplexing system of FIG. 5 is employed or the simultaneousmultiplexing system of FIG. 6 is employed, on whether a variation of thetwo is used, as has been previously described.

In a variation, the master module 370 and/or the satellite module 371may include image storage mechanisms, of the kind discussed in FIGS. 2,5 and 9, for sequential interrogation and development by multiplexingcontrols that may be contained in the control module 372. In addition tothe fixed reader stations 373 to 378 and 380 to 382, the modules mayalso be provided with the interfacing connections and circuitry of FIG.3 for receiving portable scanner or reader units of FIGS. 2 and 10.

As will be appreciated, the master module 370 and satellite module 371may be provided with different numbers of scanning stations, orconnections for portable units, to provide different copiercapabilities, and each may be housed in a separate modular cabinet ofdifferent size, or configuration, so as to be readily accomodated inavailable spatial areas of rooms or libraries. For example, arectangularly shaped module 384 as is shown in FIG. 14 may be desiredfor compact accommodation against the walls, or a pair may be used atthe corners of the room. The master module 384 of FIG. 14 may be asmaller, self-contained unit having but two optical scanner stations 387to 388 and with associated copy delivery outlets 387a and 387b. Thismaster unit 384 may contain a complete multiplexing system of the typeof FIGS. 3, 5, or 6 and therefore may be employed by itself in smalloffices or libraries. On the other hand, for users having greatercapacity needs, additional rectangular satellite modules 385 and 386 maybe detachably coupled to the master unit 384 by the universal bus system390 and 389, as shown. In this arrangement of FIG. 14, each of thesatellite units 385 and 386 may also comprise a self-containedmultiplexed copier having a pair of scan stations, and associated outletchutes, as well as having its own developer mechanism and paper supplyand feed mechanism. Alternately, each satellite unit may share some ofthe functions components with the master module 384, ranging from merelysharing its digital data processor or circuitry to providingmultiplexing operation using a common development mechanism, or othercommon mechanism as previously described, that are housed in otherseparate modules.

In FIG. 15, the modules are shown as being housed in separate L-shapedcabinets 396 and 397 that are interconnected by a universal bus 398.This shape of this module is considered to be particularly useful foraccomodation in the corners of a room, and when used in groups of four,to provide a rectangularly shaped island for placement centrally in theroom or otherwise away from the walls (not shown).

FIGS. 16 and 17 illustrate still additional configurations that areuseful for various spatially available areas. In FIG. 16, a series ofarcuately shaped modules 399 to 404, inclusive, are abutted end-to-endin series to provide an elongated C-shaped configuration. Each of themodules is provided with two optical scanner stations, such as 399a and399b, that are alternately arranged near opposite sides of the module toprovide greater working areas for the users. By abutting the modules,rather than spacing them apart as in FIGS. 13-15, inclusive, it isobvious that the entire island of copier modules occupies lesser space.

As is believed evident, there is no need for combining modules of thesame shape or configuration; whereby arcuately shaped modules may becombined with L-shaped modules, or with rectangularly shaped modules, orwith other shapes and sizes. This is generally shown in FIG. 16 by theinterconnection of an additional module 405 of L-shaped configuration tothe end arcuately shaped module 399 of the enlarged C-shaped island ofmodules using a universal bus 406.

FIG. 17 illustrates a still further variation in the shape orconfiguration of the modules to provide a compact spatial combinationhaving a plurality of optical reader stations. In this embodiment thereis provided a centrally located cylindrically shaped master module 410together with a series of five satellite modules 411 to 415, inclusive,that are of truncated pie-shape, and are peripherally arrayed about thecentral module 410, as shown. In a preferred arrangement, each of thesatellite modules 411 to 415 plugs into the central unit, by a concealeduniversal bus and concealed connector unit (not shown) whereby thecombination of all modules compactly nest together to provide a circularouter configuration, as shown. The optical scan stations for eachmodule, 416 to 420, inclusive, are so arranged and placed as to bereadily accessible by users that are circumferential spaced (not shown)about the outside of the circular island of modules.

FIG. 18 schematically illustrates but a small number of the manypossible arrangements of the differently shaped modules in an enclosedor open room or area having some walls that may be rectilinear, andothers that are arcuate; as well as in a room leading to small alcoves,hallways, and other areas. As will be appreciated, the arrangementsshown are merely a very few of the many possible configurations that maybe employed using the differently shaped modules proposed by the presentinvention.

As shown, away from the walls and toward the center of the room may beprovided a rectangular island comprised of four confrontinginterconnected L-shaped modules 425 to 428, inclusive. Also away fromthe walls, may be provided a circular island comprised of twosemicircular banks of modules 429 and 430. Still a further arcuateisland of modules may be provided in an enlarged C-shaped bank ofinterconnected modules 431.

At the lower right hand corner of the room may be provided an L-shapedcopier module 432 combined with a satellite module 433 of rectangularconfiguration, located against the wall to supply added copier capacity.At the upper right-hand wall, disposed on at angle to its adjoiningwalls, can be accommodated a linearly arranged series of rectangularlyshaped modules 434 to 436, inclusive, that are abutted against eachother, and are interconnected with a still further spaced apartrectangular module 437.

For the upper left hand curved wall, there can be provided threearcuately shaped modules 440 to 442, inclusive, that are abuttedend-to-end, and disposed against the wall to also provide a compactarrangement. For use in narrow rectangular hallways, alcoves, and otherlike spaces, a pair of L-shaped modules 443 and 444 may be employed; ora series of rectangularly shaped modules (not shown).

Pie shaped modules 445 to 448 may be combined to also provide centralislands of copiers in the room. However, this configuration providesaccess to users only at the outside periphery whereas the other "hollow"island configurations shown provides access both inside and outside theisland, but less desirably, occupies a greater spatial area than thepie-shaped modules.

To optimize the utility of the system for greatest applicability todifferent users, both large and small, it is preferred that a variety ofdifferently shaped master and satellite module be made available, allwith common (or universal bus) interconnection means so that thedifferent units may be intercombine together in various ways to satisfyboth the copy making capability needed by the user, and also to providethe different spatial configurations that may be suitably accommodatedwithin the users available rooms or areas. If required for the purposeof providing still greater versatility, the individual modulesthemselves may be made in modular form, so that a given cabinet orhousing configuration may contain a greater, lesser, or different kindof functional component or part of the copier system. In this manner,optimized systems may be assembled that are best tailored for the needsof the particular users.

All of the differently shaped housing modules described and shown inFIGS. 13 to 18, inclusive, are preferably provided with plug-inreceptacles and associated multiplex circuitry, as described above inFIGS. 1, 2, and 3 for use with the portable "camera" units of FIGS. 1,2, 7, 8, and 10 discussed above. Such modules are also provided with TVdisplay screens 109 as described. If desired, separate modules may beprovided with only plug-in receptacles, circuitry, and display withoutfixed optical reader stations.

FIG. 9 shows a preferred copy sheet feed and automatic copy separationsub-system, for delivering each of the copies to a different one of aplurality of copy outlets 221, 222 and 223 corresponding to, orassociated with, the particular one of the optical scan stations, suchas 226, 228 and 229, where that image originated from, as employed inthe on-line, off-line system of FIG. 5.

Presupposing the operation of optical scan station 226, the opticalimage of the document being read at that station is either applieddirectly to optical imager 224 for direct application to an led lightbank 202 and exposure of photoconductor 200 in an on-line manner, or theimage is alternatively entered into an available one of the memory units225, 227 for off-line operation, as is described above in the operationof FIG. 5. In either event, a latent electrostatic charged image of thatdocument being read is formed on a photoconductor drum 200, that hasbeen previously charged by high voltage charger 201. Concurrently withthe application of this image to the drum 200, or memory, the scanstation 226 also transmits a simple unique code in the form of dots orbars that serves to identify and distinguish that station 226 over otheroptical stations, such as 228 or 229. For example, station 228 may beassigned simple code of "1" dot by means of a simple permanent visibledot marking located at the base of the glass platen upon which theoriginal document is placed for scanning, station 226 may be assigned adifferent code of "2" by using two such permanent black dots on itsglass platen [not shown] and station 229 assigned a code of "3". Afterreading the image on the document, the light beam at station 226 alsotransmits this code of "2" [two dots] to the memory or imager 224 andlight bank 202, and ultimately both the image on the document and theidentity code "2" of station 226 are applied to the photoconductor 200to be reproduced. This latent identity code image is reproduced invisible form along with the image of the document when the toner 204 isapplied to the drum 200 during development, and both the toned visibleimage and identity code area, in turn, transferred to a copy sheet 205that is fed to the drum 200 by a paper feed mechanism 203.

After receiving by transfer from the drum 200 both the tone image andidentity code, the copy sheet now located at position 205a is thendelivered to a conveyor 208 for ultimate delivery to an outlet. However,first it is carried past an optical code detector 209 where the uniqueidentity code "2" on the copy is read by the detector 209. Code detector209, employing photocells, energizes a logic circuit 210 that, in turn,selectively actuates a proper one of a series of deflector gates 212,213, or 214 according to the particular code detected. Presupposing thatcopy outlet 222 is associated with optical scanner station 226, thedetection of dot code "2" on the copy at position 205a is noted andoutlet logic circuit 210 operates the proper deflection gate 213,leading to channel 219 and to the correct copy outlet 222.

As shown, the series of gates 212, 213, and 214 are disposed in spacedapart arrangement along the path of the document being fed by theconveyor sections 208, 215, 216, and 217. Therefore the actuation of thegate 213 diverts the document at position 205c into outlet channel 219leading to proper copy outlet 222. All of these different copy receivingoutlets 221, 222, 223, and others, may be provided close together in asingle or double bank as shown in module 72 in FIG. 13, or alternativelythey may be displaced apart from one another and disposed alongsidetheir associated optical scanning stations, as shown in FIGS. 4, 14, and15.

An alternative system for automatically separating and feeding copiesinto different outlets according to different digital codes on thedocuments is disclosed in U.S. Pat. Nos. 3,650,204 and 3,804,005. Inthese patents the different copy receiving outlets are disposed in acommon area alongside each other as in the embodiment of FIG. 13.

FIG. 10 shows the simultaneous reading of a document image by a portablecamera unit, that may include a chargedcoupled photosensor receptorarray 301 coupled to a memory or storage 303 for retaining the opticalimage. As shown, the camera unit preferably includes a syncronizedelectronic flash transmitter 304 for illuminating the document 300 withhigh intensity light, and a focusable lens 305 for applying thereflected image from the document to the solid state sensor 301.Conventional charge coupled sensor units have an inherant memorycapacity, and are incrementally scannable by a clock 302 and shiftregister 307 to read-out the image in electrical form over an outputline 308 to the memory or recorder 303. The focusable lens system 305may be provided as an adjustable zoom lens to permit documents ofdifferent sizes and shapes to be focused upon the CCD sensor array 301.

In the same manner as discussed above in FIGS. 1 and 2, the observedimage from document 300 is stored or retained in either electrical ormagnetic form in the memory 303, and may be reproduced at theconvenience of the user by coupling the portable "camera" unit to anavailable copy making reproduction unit as described above in FIG. 1.Many different solid state cameras of this kind are presently available,and a further description herein is therefore considered to beunnecessary.

FIG. 11 discloses a preferred circuit for providing an automatic displayor an audible annunciation of any malfunction to the user, and/or anautomatic shutoff of the entire machine, or any individual sectionsthereof, in the event of any such malfunction.

As shown in FIG. 11, each of the individual functioning units of themachine is provided with one or more electrical transducers 400, 401,402, 403, 419 and the like, for monitoring its performance, andproducing an electrical signal corresponding to the sensed condition.These signals are digitized by conventional A to D convertors 404 to 407and 420, and each monitored digitized signal is then applied to acomparator circuit including 412 to 415 and 422 where it is compared toa preset point or reference 423 to 427, inclusive. All of the essentialsub-systems employed in the multiplexed machine are monitored in thismanner and in the event of malfunction of any such essential system, amalfunction signal is directed to "OR" circuit 416 that directs ashut-off signal to the shut-off power relay circuit 417 fordisconnecting the power from the various stations. Additionally, thisshut-off signal from "OR" circuit 416 is applied to a display and/orannunciator circuit 418 to visually indicate and/or audibly announce thesource of the malfunction. The display and annunciator 418 also isenergized by each of the comparator circuits 412 to 415 and 422 toidentify the source of the malfunction. This, for example, should thepaper feed subsystem suffer a jam or otherwise malfunction, a signal isproduced by a paper feed detecting transducer 400 and is determined tobe a malfunction by comparison of this signal with that of set reference423. Since the proper paper feed operation is essential to all opticalstations [in the event of a single paper feed for all stations], theresulting malfunction signal is directed through "OR" circuit 416 to theshut-off power circuit 417 thereby to deenergize all of the optical scanstations. Additionally, the same shut-off signal is applied to thedisplay and annunciator circuit 418. A second signal from the paperdetecting channel is directed from comparator 412 to the display circuit418 to identify the cause of the malfunction, and the combination ofthese two signals are employed to energize the appropriate displaymessage [visual and/or audible] to notify the users and the repairpersonnel of the cause for malfunction.

In addition to monitoring and controlling those sub-systems thatcommonly affect all optical reader stations, it is preferred to providesimilar controls for selectively disconnecting the power and displayingthe malfunction of individual ones of the stations where suchmalfunction would only affect the operability of only that station butnot the others. This is performed in a similar manner by monitoring thesub-systems of specific stations such as the optical reader 430, theoutlet gates for those stations, the on-off, coin operated and othercontrols for each such station, and other functioning sub-systems forthe individual stations. These monitored signals that only affectindividual ones of the channels are processed in a similar manner, byconverting the transduced signals into digital form by A to Dconvertors, such as 431; comparing the signals to a preset reference 433in comparator 432; and applying any malfunctioning resulting signal tothe partial shut-off circuit 438. However, unlike the main powerdisconnect 417 that disconnects all power, the partial shut-off 438disconnects only the power to the affected channel relating to thatparticular malfunctioning scan station. A separate display and audiblesignaling sub-system 439 is provided from each channel and thisdisplay/indicator 439 is energized by both the malfunction error signal,the shut-off signal from 438, and the command signal from the on-off orcoin operated control 440. Upon the user requesting a copy function byoperation of switch 440, the display/indicator 439 signals the presenceof the particular malfunction and returns the coin, if necessary. Eachscan channel is provided with a number of transducers, such as 430, andassociated circuits, to monitor the essential functions and allresulting "error" or "malfunction" signals for each channel are coupledthrough "OR" circuit 434, as shown, to operate the partial shut-off 438and display/indicator 439 in the manner described. FIG. 12 shows amultiplexed photocopying system similar to FIG. 5, and operating in anon-line, off-line mode, but employing integrated logic circuitry insteadof a microprocessor, for controlling the multiplexing operations. Thesystem shown includes a pair of independantly operable scanning stations500 and 501 combined with image storage or a recorder 502, formultiplexing off-line operation as previously described. Additionallythe system includes a common electrostatic developer mechanism formaking "hard" copies of the scanned images and including aphotoconductor drum 503 having a high voltage charger 504, an LED typevisual image former 505, a toner or developer feed 506, and a paper feed507, all being of a conventional construction as is now well known inthe art.

To enable the described multiplexing operation, each of the opticalreader stations 500 and 501 is provided with selectively operable gatemeans for either applying the scanned image to be applied directly tothe photoconductor 503 in real-time for on-line development, oralternatively transferring the visual image to reproduced into thememory or storage 502 for "off-line" later development into a "hard"copy, when the common development mechanism that is shared by the tworeaders 500 and 501 becomes available.

As previously discussed, the optical reader or scan station 500, 501observe the printed or graphic data to be reproduced employingphotocells, CCD's and like optical-electrical readers, and produceelectrical data signals, in either analog or digital form, as theiroutputs. The gating means, to be described, are conventional electricalcircuitry for selective transmission or blocking of the electricaloutput data signals from the scan stations.

Returning to FIG. 12, the output of the first scan station 500 isdirected to gate means 508 for selective transmission of the datasignals directly to the LED video imager 505, through "OR" circuit 512,and is also directed to gate means 509 for alternative selectivetransmission to the image storage medium 502. Similarly the secondoptical scan station 501 likewise has its output directed to gate means511 for direct on-line transmission to the LED video imager 505, oralternatively, its output is selectively directed to the second gatemeans 510 for off-line storing of the video image signal in the memoryor storage 502.

For controlling the selective operation of these various gates, there isprovided a digital logic circuit that responds to two conditions of thesystem at the time that each request for making a copy is made to decidewhether the video data to be reproduced need be temporarily stored forlater development. The first condition that is considered is whether ornot the common developer mechanism is already engaged in cycling at thetime a request for copying is made. This first condition is detected bya transducer 514 that continuously monitors the photoconductor drum 503to determine whether it is cycling; and if so, produces a TACH signal tothe AND circuit 515 associated with the first scan station 500, and alsodirects the TACH signal to the AND circuit 520 associated with thesecond scan station 501.

The AND circuit 514 is also energized by the "on" or command switchsignal [eg. coin operated] from the first scan station 50. Therefore, inthe event of a command signal produced by the first optical station 500when the machine is already cycling or developing a previous copy, theAND circuit 514 is enabled to open or "turn-off" the gate 508, andthrough an inverter circuit 518 alternatively functions to concurrently"turn-on" or close the second gate 509. Opening of gate 508 prevents thevideo signal from scan station 500 from going directly to the imager 505for photoconductor 503, and the concurrent closing of gate 509 directthis video signal into the memory 502 for temporary storage of the videoimage in an off-line manner.

The second condition that is monitored by this logic circuit is whetheror not a previously entered video image is preexisting in the storage ormemory 502 at the time of a new command received at station 500 to makea copy. This function is performed by employing a flag transducercoupling the memory 502 to a second AND gate 516 associated with thefirst scan station 500. This second AND gate 516 is also energized bythe "on" command or start signal from the first scan station 500 wherebyin the event of a new command received from station 500 and theconcurrent presence of a previously stored video signal, the second ANDgate 516 is activated to "open" or deactivate the gate 508, and to closethe gate 509, thereby directing the new video image from scan station500 into the memory 502. On the other hand, if the developer mechanismis not cycling and there is no preexisting video image stored in thememory 502, a new command for copying received by optical station 500permits this station to function in an on-line manner and apply itsvideo image directly through normally closed gate 508 to the imageformer 505 for direct application of the video image to thephotoconductor drum 503.

The logic circuitry for the second [and/or additional] optical station501 is the same as previously described, and includes an AND gate 520for controlling off-line operation responsively to a command received bystation 501 when the developer is cycling, and an AND gate 521 forcontrolling "off-line" operation in the event of a previously storedvideo image in the memory 502. Thus any previously stored video imagesheld in the memory 502 are developed first, or given priority indevelopment, over any new command to copy received by either opticalstaion 500 or 501.

A gate circuit 513 is disposed in the read-out channel from the memory502 to prevent application of the stored video image into the videoimager 505 until such time as the developer mechanism has completed itsprevious cycle and is readiness to receive and make the next copy. Thisgate 513 is maintained "off", or is opened, to prevent inadvertanttransmission of the stored video signal by the transducer signal from514 that monitors the cycling condition of the developer mechanism. Whenthe developer mechanism completes its previous cycle, the gate means 513is closed to read-out the stored image from the memory 502 and apply itto the drum 503 via the LED imager. The developer mechanism iscontrolled by conventional power relays [not shown] to initiate itscycling mode of operation concurrently with the closure of any one ofgates 508, 511, or 513 thereby to selectively respond to the scanstations or memory and reproduce the "hard" copies when commanded to doso. As previously discussed, higher speed developer mechanisms arepresently available than the time required by individual users to placeand remove the masters into and out of the machine. Consequently themachine of the present invention is capable of almost continualoperation to rapidly supply the needs of a waiting line of users.

The video image storage unit 502 may comprise a magnetic disc, drum, webor other memory or recorder for storing a number of video images [numberof documents]. The recording and readout of the video images fromstorage is preferably arranged to provide priority to the earliestentries whereby the earliest users receive their hard copies first, inthe same order as their use of the scan stations. Alternatively, if thememory units being employed are capable of retaining in storage only onedocument at a time, a series of such memories may be used, with theplural memories being sequentially interrogated for read-out by asuitable clock means and shift register to afford the same priority ofuse.

It will be appreciated that the present invention contemplates that morethan two scan stations may be multiplexed to a lesser number of memoriesand to one or more common development mechanisms. For such systems ofgreater complexity, the logic circuitry governing the on-line oroff-line mode of operation of each station is the same as previouslydescribed, to always afford priority to the earliest users.

I claim:
 1. A copier system having plural independantly operable opticalreader stations and a fewer number of developer mechanisms for producinghard copy reproductions of visual images read by said optical readerstations, malfunction indication and control means, said malfunctionindication and control means including monitoring means for thoseoperating components of the system that affect only individual readerstations for detecting malfunction of those components, and control andindicator means for each station for deenergizing only the affectedstations in response to unacceptable malfunction thereof and indicatingthe source of malfunction of the affected stations, and additionalmonitoring means for those operating components of the system thataffect all stations, and additional control and indicator means fordeenergizing the entire copier system in response to unacceptablemalfunction thereof and indicating the source of malfunction.
 2. In thesystem of claim 1, said indicator means comprising a visual indicator.3. In the system of claim 1, said indicator means comprising an audibleindicator.
 4. In the system of claim 1, said indicator means comprisingboth a visual and an audible indicator.
 5. In the system of claim 1,said indicator means for each station responsive to a user requesting acopy function by a reader station to actuate said indicator.
 6. Anelectrostatic copier system having plural optical reader stations atleast one of which is detachably connectable to the system and adeveloper mechanism incapable of printing from all stationssimultaneously for multiplexing application to the different readerstations according to the priority of usage of the stations, a pluralityof "hard copy" delivery outlets each associated with a different one ofthe optical reader stations, means for identifying the video imagesproduced by each station, and sorting means responsive to saididentifying means for delivering each "hard copy" reproduction to thecorrect delivery outlet, the addition of malfunction indication andcontrol means, said malfunction means comprising means for monitoringthose components of the machine that affect all stations anddeenergizing the entire machine in response to unacceptable malfunctionthereof, and additional means for monitoring those components of themachine that are associated with only particular reader stations anddeenergizing only the affected station in response to unacceptablemalfunction thereof, and indicator means associated with saidmalfunction means and additional means for indicating the source ofmalfunction.
 7. In the system of claim 6, said indicator meanscomprising an audible indicator.
 8. In the system of claim 6, saidindicator means comprising a visual indicator.
 9. In the system of claim6, said indicator means comprising both a visual and an audibleindicator.
 10. In the system of claim 6, said indicator means for eachstation responsive to a user requesting a copy function by a readerstation to actuate said indicator.